'Who is the oldest person you have ever met?'

Or to put it another way: of all the people who you remember meeting, who was born the earliest?

Think carefully before you answer and rest assured: whatever answer you give will probably be more interesting and impressive than my own.

Aside from the fact that I am a historian myself and the unexceptional truth that I was born in the late 1970s and lived for an as yet undetermined period of time after that, I doubt my own life would be of much interest to future historians.

I once saw Princess Diana when she visited my school in 1991 and have been lucky enough to meet and interview several famous people such as the actors John Hurt, Natalie Portman and Stephen Fry.

But while one of my friends can claim to have met the former Prime Minister, Harold Macmillan (1894-1986) when he was a child, I cannot even definitely be sure I have even met anyone famous or otherwise who was born in the 19th century.

In 1988, the children’s author, HE Todd, the creator of the Bobby Brewster books, visited my school. I remember, we were saddened to hear of his death shortly afterwards.

Although he is not exactly a household name these days, it is easy enough for me to find out today that he was born in 1908. I didn’t exactly “meet” him either but sadly this seems to be the best I can do.

My parents are very far from being the oldest people I have ever met. Both were born during the Second World War. They have lived and full lives and can remember such events as the Queen’s coronation in 1953, the assassination of President Kennedy in 1963 and the long hot summer of 1976.

My mother’s parents were both born during the First World War. My maternal grandfather was born in August 1914, the fateful month the war started. My grandmother was born in Dublin in 1916: the famous Easter Rising had rocked that city only a few weeks before. Her own father had served with the British Army and had been wounded in the disastrous Gallipoli campaign of 1915.

Their family soon moved to England after my great-grandfather had come close to being shot by one of the notorious Black and Tans who roamed Ireland in the period after 1918.

My maternal grandparents settled in Nuneaton and were close to Coventry when it was bombed in 1940.

My father grew up in the pleasant Wiltshire village of Limpley Stoke. As a boy, he shared the excitement of the local community when certain scenes from the Ealing comedy film, The Titfield Thunderbolt were filmed there in 1952.

He also remembers speaking to an old lady who remembered sailing across the sea in a sailing ship. As a young man he distinctly remembers two old men who worked in his office who would reminisce about their experiences in the trenches during the First World War.

Today, my parents’ youngest grandchild – my own niece - recently celebrated her ninth birthday.

She was born in 2013 and as things stand it seems entirely plausible that she could still be alive in the early years of the next century. I don’t know about you, but this sort of thing boggles my mind.

As children, my own parents must have encountered old people such as their own grandparents, who had been born in the year 1870 or before, people who must have once breathed the same air as Charles Dickens or who had seen Paris before the Eiffel Tower.

Yet within their own lifespans they have also encountered the young children who will one day inhabit the 22nd century.

It is astonishing to think within the span of an ordinary human life most of us will get to meet a range of people whose lives will together span something close to around three human lifespans, a period encompassing perhaps over 240 years.